#
#------------------------------------------------------------------------------
# purpose: to run a command, log cmd output, exit on error
# usage:
# set -e; do_run_cmd_or_exit "$cmd" ; set +e
#------------------------------------------------------------------------------
do_run_cmd_or_exit(){
    cmd="$@" ;

    do_log "DEBUG running cmd or exit: \"$cmd\""
    msg=$($cmd 2>&1)
    export exit_code=$?

    # If occurred during the execution, exit with error
    error_msg="Failed to run the command:
        \"$cmd\" with the output:
        \"$msg\" !!!"

    if [ $exit_code -ne 0 ] ; then
        do_log "ERROR $msg"
        do_log "FATAL $msg"
        do_exit "$exit_code" "$error_msg"
    else
        # If no errors occurred, just log the message
        do_log "DEBUG : cmdoutput : \"$msg\""
    fi

}

http://cfaj.freeshell.org/shell/cus-faq-2.html#11

How do I get the exit code of cmd1 in cmd1|cmd2 First, note that cmd1 exit code could be non-zero and still don't mean an error. This happens for instance in cmd | head -1 You might observe a 141 (or 269 with ksh93) exit status of cmd1, but it's because cmd was interrupted by a SIGPIPE signal when head -1 terminated after having read one line. To know the exit status of the elements of a pipeline cmd1 | cmd2 | cmd3 a. with Z shell (zsh): The exit codes are provided in the pipestatus special array. cmd1 exit code is in $pipestatus[1], cmd3 exit code in $pipestatus[3], so that $? is always the same as $pipestatus[-1]. b. with Bash: The exit codes are provided in the PIPESTATUS special array. cmd1 exit code is in ${PIPESTATUS[0]}, cmd3 exit code in ${PIPESTATUS[2]}, so that $? is always the same as ${PIPESTATUS: -1}. ... For more details see Z shell.

如果你想用$?，您将需要在每个命令后检查它，因为$?在每个命令退出后更新。这意味着如果您执行一个管道，您将只获得管道中最后一个进程的退出码。

另一种方法是这样做:

set -e
set -o pipefail

如果将它放在shell脚本的顶部，Bash似乎会为您处理它。正如前面的帖子所指出的，“set -e”将导致Bash在任何简单命令上都出错退出。"set -o pipefail"将导致Bash在管道中的任何命令上都出错而退出。

有关这个问题的更多讨论，请参见这里或这里。下面是Bash手册中关于内置设置的部分。

在Bash中，这很简单。用&&把它们连在一起:

command1 && command2 && command3

你也可以使用嵌套的if结构:

if command1
   then
       if command2
           then
               do_something
           else
               exit
       fi
   else
       exit
fi

#
#------------------------------------------------------------------------------
# purpose: to run a command, log cmd output, exit on error
# usage:
# set -e; do_run_cmd_or_exit "$cmd" ; set +e
#------------------------------------------------------------------------------
do_run_cmd_or_exit(){
    cmd="$@" ;

    do_log "DEBUG running cmd or exit: \"$cmd\""
    msg=$($cmd 2>&1)
    export exit_code=$?

    # If occurred during the execution, exit with error
    error_msg="Failed to run the command:
        \"$cmd\" with the output:
        \"$msg\" !!!"

    if [ $exit_code -ne 0 ] ; then
        do_log "ERROR $msg"
        do_log "FATAL $msg"
        do_exit "$exit_code" "$error_msg"
    else
        # If no errors occurred, just log the message
        do_log "DEBUG : cmdoutput : \"$msg\""
    fi

}

[ $? -eq 0 ] || exit $?; # Exit for nonzero return code